1. Field of the Invention
The present invention relates to a golf club head and a golf club.
2. Description of the Related Art
Performances of golf club heads vary depending on the weight distribution in the head. Effective means for improving the control performances and flight distance performances include lowering of the center of gravity, deepening of the center of gravity, and increase in moment of inertia, and the like.
In attempts of lowering the center of gravity, deepening the center of gravity, and increasing the moment of inertia, a weight member having a specific gravity greater than that of the head main body may be used. Because this weight member has a specific gravity greater than that of the head main body, the degree of freedom in regulating the weight distribution in the head can be elevated. Also, when the weight member is exposed, the presence of the weight member may be visually perceptible. The exposed weight member can make an appeal to golf players for the excellent head performances.
The weight member is provided as a separate member from the head main body. The weight member is attached to the head main body. Upon hitting, the weight member receives a great impact. The weight member must be firmly attached to the head main body. JP-A No. 2000-176059 discloses a technique for engaging the head main body with the weight member by means of an undercut part or a circumferential groove. A USA counterpart to the JP-A No. 2000-176059 is U.S. Pat. No. 6,379,265.
In the aforementioned prior art technique, the weight member is press fitted into the head main body. Upon the press fitting, strong force is imparted to the boundary part between the weight member and the head main body. The press fitting may partially deform the boundary part between the head main body and the weight member, or may readily yield a nonuniform gap between the head main body and the weight member in the boundary part. The press fitting may readily deteriorate the good-looking appearance of the boundary part between the head main body and the weight member.
As other technique for joint, welding of the head main body and the weight member may be suggested. In case of the welding, nonuniform weld bead, traces of the polishing thereof and the like are apt to be provided. In such cases of the welding, good-looking appearance of the boundary part between the head main body and the weight member may be readily deteriorated.
As other technique for the joint, screw cramping of the head main body with the weight member may be suggested. In case of the screw cramping, likelihood of detachment of the weight member due to repeated impact is comparatively greater than that in cases of other joining processes. Interpositioning of an engaging member between the head main body and the weight member may also be suggested. When the engaging member is interpositioned, the structure is apt to be complicated, and may result in elevation of the cost for the members, and for production of the head.